Research On Frequency Hopping Signal Detection And Parameter Estimation For UAV

Along with the rapid development of computer information technology,the use of UAV(Unmanned Aerial Vehicle)gradually extend from military field to civil domain.Civil UAV has the characteristics of miniaturization,simple operation,and can carry different equipment to finish different tasks,at the same time,it also has the functions of aerial photography,monitoring,remote dispatch,plant protection,transportation and so on,more and more popular with consumers.In the process of rapid development of UAV,bring with some problems,for example,a weak sense of security of consumers,and imperfect policies and regulations,which make the “illegal flight” more and more serious.An important technical means to solve this problem is to detect and estimate the parameters of UAV flight control signals,and complex electromagnetic environment and frequency hopping communication mechanism make it difficult to detect and estimate UAV flight control signals.Therefore,it is of great significance and practical application value to study the detection and parameter estimation of UAV frequency hopping signal.The core content of this paper is as follows:(1)The system composition,communication principle and frequency hopping signal characteristics of UAV are introduced,and analysis the main methods of UAV frequency hopping signal from the aspect of time domain and frequency domain.Through the analysis of the characteristics of the existing frequency hopping signals,point the key points of frequency hopping signal detection.(2)Summarize and analysis the characteristics of frequency hopping signal of UAV,considering the electromagnetic environment of UAV frequency hopping signal and the difference of signal and noise distribution in time domain,An adaptive threshold calculation method is proposed,and do experiments under different electromagnetic environments,the results show the method can effectively remove noise.Based on a series of characteristics of frequency hopping signal,the application of clustering analysis algorithm in frequency hopping signal detection is analyzed.(3)An improved clustering algorithm is proposed.This algorithm does not need to set the number of classifications and takes advantage of the density clustering algorithm,can adaptive classification of data.By constructing waveform shape and peak energy characteristics of frequency hopping signal of UAV,apply the improved clustering analysis algorithm to frequency hopping signal detection and parameter estimation of UAV.The algorithm proposed in this paper has been tested under different electromagnetic conditions,and compared with K-means,K-means++,DBSCAN and multiple-hopauto-correlation algorithms,frequency hopping signal detection and parameter estimation,The results show that the proposed algorithm has high accuracy,low error detection rate and good stability.